Input: add driver for the Cypress CY8CTMA140 touchscreen

Input: add driver for the Cypress CY8CTMA140 touchscreen

This adds a new driver for the Cypress CY8CTMA140 touchscreen.

This driver is inspired by out-of-tree code for the Samsung
GT-S7710 mobile phone.

I have tried to compare the structure and behaviour of this
touchscreen to the existing CYTTSP and CYTTSP4 generics and
it seems pretty different. It is also different in character
from the cy8ctmg110_ts.c. It appears to rather be vaguely
related to the Melfas MMS114 driver, yet distinctly
different.

Dmitry Torokhov rewrote the key scanning code during the
submission process so the driver is a joint work.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200506123435.187432-2-linus.walleij@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>